[zachmorris]

Thanks @Wintermute0110 and @garbear,

Using your hints and the existing kodi-game-scripting stuff on github, I was able to throw something together to build game addons from the buildbot. I have started a repository here and I'm currently testing it out (currently only includes a handful of cores for OSX, Windows and Linux x86_64), but I've got a script that will build addons for all the platforms I think are possible with Kodi and the libretro buildbot. Build of all of them took maybe 5 minutes (most time required was just downloading the latest cores).

Most every core seems to work as you suggested and a few don't likely for the compiling incompatibility reasons you mentioned. I only tested the OSX built addons, but linux users could try installing by zip the addons in the linux folder of the repo above. I'll keep working on this script to get it a little more robust, but it seems like a reasonably good way to generate kodi game addons.

Here's a few examples I've tried that work:
Flycast WinCE
PocketCDG

Mesen-S
BSNES
Cannonball
FBNeo
MAME (latest)